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path: root/drivers/hwmon/sht15.c
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Diffstat (limited to 'drivers/hwmon/sht15.c')
-rw-r--r--drivers/hwmon/sht15.c327
1 files changed, 154 insertions, 173 deletions
diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c
index 91fdd1fe18b..97cd45a8432 100644
--- a/drivers/hwmon/sht15.c
+++ b/drivers/hwmon/sht15.c
@@ -1,7 +1,7 @@
/*
* sht15.c - support for the SHT15 Temperature and Humidity Sensor
*
- * Portions Copyright (c) 2010-2011 Savoir-faire Linux Inc.
+ * Portions Copyright (c) 2010-2012 Savoir-faire Linux Inc.
* Jerome Oufella <jerome.oufella@savoirfairelinux.com>
* Vivien Didelot <vivien.didelot@savoirfairelinux.com>
*
@@ -24,12 +24,12 @@
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/mutex.h>
+#include <linux/platform_data/sht15.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/err.h>
-#include <linux/sht15.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/atomic.h>
@@ -53,6 +53,9 @@
#define SHT15_STATUS_HEATER 0x04
#define SHT15_STATUS_LOW_BATTERY 0x40
+/* List of supported chips */
+enum sht15_chips { sht10, sht11, sht15, sht71, sht75 };
+
/* Actions the driver may be doing */
enum sht15_state {
SHT15_READING_NOTHING,
@@ -136,12 +139,12 @@ static const u8 sht15_crc8_table[] = {
* @reg: associated regulator (if specified).
* @nb: notifier block to handle notifications of voltage
* changes.
- * @supply_uV: local copy of supply voltage used to allow use of
+ * @supply_uv: local copy of supply voltage used to allow use of
* regulator consumer if available.
- * @supply_uV_valid: indicates that an updated value has not yet been
+ * @supply_uv_valid: indicates that an updated value has not yet been
* obtained from the regulator and so any calculations
* based upon it will be invalid.
- * @update_supply_work: work struct that is used to update the supply_uV.
+ * @update_supply_work: work struct that is used to update the supply_uv.
* @interrupt_handled: flag used to indicate a handler has been scheduled.
*/
struct sht15_data {
@@ -163,8 +166,8 @@ struct sht15_data {
struct device *hwmon_dev;
struct regulator *reg;
struct notifier_block nb;
- int supply_uV;
- bool supply_uV_valid;
+ int supply_uv;
+ bool supply_uv_valid;
struct work_struct update_supply_work;
atomic_t interrupt_handled;
};
@@ -209,11 +212,13 @@ static u8 sht15_crc8(struct sht15_data *data,
*
* This implements section 3.4 of the data sheet
*/
-static void sht15_connection_reset(struct sht15_data *data)
+static int sht15_connection_reset(struct sht15_data *data)
{
- int i;
+ int i, err;
- gpio_direction_output(data->pdata->gpio_data, 1);
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSCKL);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
@@ -223,6 +228,7 @@ static void sht15_connection_reset(struct sht15_data *data)
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
}
+ return 0;
}
/**
@@ -248,10 +254,14 @@ static inline void sht15_send_bit(struct sht15_data *data, int val)
* conservative ones used in implementation. This implements
* figure 12 on the data sheet.
*/
-static void sht15_transmission_start(struct sht15_data *data)
+static int sht15_transmission_start(struct sht15_data *data)
{
+ int err;
+
/* ensure data is high and output */
- gpio_direction_output(data->pdata->gpio_data, 1);
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
@@ -267,6 +277,7 @@ static void sht15_transmission_start(struct sht15_data *data)
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
+ return 0;
}
/**
@@ -290,13 +301,19 @@ static void sht15_send_byte(struct sht15_data *data, u8 byte)
*/
static int sht15_wait_for_response(struct sht15_data *data)
{
- gpio_direction_input(data->pdata->gpio_data);
+ int err;
+
+ err = gpio_direction_input(data->pdata->gpio_data);
+ if (err)
+ return err;
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
if (gpio_get_value(data->pdata->gpio_data)) {
gpio_set_value(data->pdata->gpio_sck, 0);
dev_err(data->dev, "Command not acknowledged\n");
- sht15_connection_reset(data);
+ err = sht15_connection_reset(data);
+ if (err)
+ return err;
return -EIO;
}
gpio_set_value(data->pdata->gpio_sck, 0);
@@ -314,12 +331,13 @@ static int sht15_wait_for_response(struct sht15_data *data)
*/
static int sht15_send_cmd(struct sht15_data *data, u8 cmd)
{
- int ret = 0;
+ int err;
- sht15_transmission_start(data);
+ err = sht15_transmission_start(data);
+ if (err)
+ return err;
sht15_send_byte(data, cmd);
- ret = sht15_wait_for_response(data);
- return ret;
+ return sht15_wait_for_response(data);
}
/**
@@ -349,9 +367,13 @@ static int sht15_soft_reset(struct sht15_data *data)
* Each byte of data is acknowledged by pulling the data line
* low for one clock pulse.
*/
-static void sht15_ack(struct sht15_data *data)
+static int sht15_ack(struct sht15_data *data)
{
- gpio_direction_output(data->pdata->gpio_data, 0);
+ int err;
+
+ err = gpio_direction_output(data->pdata->gpio_data, 0);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSU);
@@ -359,7 +381,7 @@ static void sht15_ack(struct sht15_data *data)
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_data, 1);
- gpio_direction_input(data->pdata->gpio_data);
+ return gpio_direction_input(data->pdata->gpio_data);
}
/**
@@ -368,14 +390,19 @@ static void sht15_ack(struct sht15_data *data)
*
* This is basically a NAK (single clock pulse, data high).
*/
-static void sht15_end_transmission(struct sht15_data *data)
+static int sht15_end_transmission(struct sht15_data *data)
{
- gpio_direction_output(data->pdata->gpio_data, 1);
+ int err;
+
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
+ return 0;
}
/**
@@ -407,17 +434,19 @@ static u8 sht15_read_byte(struct sht15_data *data)
*/
static int sht15_send_status(struct sht15_data *data, u8 status)
{
- int ret;
-
- ret = sht15_send_cmd(data, SHT15_WRITE_STATUS);
- if (ret)
- return ret;
- gpio_direction_output(data->pdata->gpio_data, 1);
+ int err;
+
+ err = sht15_send_cmd(data, SHT15_WRITE_STATUS);
+ if (err)
+ return err;
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
sht15_send_byte(data, status);
- ret = sht15_wait_for_response(data);
- if (ret)
- return ret;
+ err = sht15_wait_for_response(data);
+ if (err)
+ return err;
data->val_status = status;
return 0;
@@ -443,7 +472,7 @@ static int sht15_update_status(struct sht15_data *data)
|| !data->status_valid) {
ret = sht15_send_cmd(data, SHT15_READ_STATUS);
if (ret)
- goto error_ret;
+ goto unlock;
status = sht15_read_byte(data);
if (data->checksumming) {
@@ -455,7 +484,9 @@ static int sht15_update_status(struct sht15_data *data)
== dev_checksum);
}
- sht15_end_transmission(data);
+ ret = sht15_end_transmission(data);
+ if (ret)
+ goto unlock;
/*
* Perform checksum validation on the received data.
@@ -466,27 +497,27 @@ static int sht15_update_status(struct sht15_data *data)
previous_config = data->val_status & 0x07;
ret = sht15_soft_reset(data);
if (ret)
- goto error_ret;
+ goto unlock;
if (previous_config) {
ret = sht15_send_status(data, previous_config);
if (ret) {
dev_err(data->dev,
"CRC validation failed, unable "
"to restore device settings\n");
- goto error_ret;
+ goto unlock;
}
}
ret = -EAGAIN;
- goto error_ret;
+ goto unlock;
}
data->val_status = status;
data->status_valid = true;
data->last_status = jiffies;
}
-error_ret:
- mutex_unlock(&data->read_lock);
+unlock:
+ mutex_unlock(&data->read_lock);
return ret;
}
@@ -508,7 +539,9 @@ static int sht15_measurement(struct sht15_data *data,
if (ret)
return ret;
- gpio_direction_input(data->pdata->gpio_data);
+ ret = gpio_direction_input(data->pdata->gpio_data);
+ if (ret)
+ return ret;
atomic_set(&data->interrupt_handled, 0);
enable_irq(gpio_to_irq(data->pdata->gpio_data));
@@ -521,9 +554,14 @@ static int sht15_measurement(struct sht15_data *data,
ret = wait_event_timeout(data->wait_queue,
(data->state == SHT15_READING_NOTHING),
msecs_to_jiffies(timeout_msecs));
- if (ret == 0) {/* timeout occurred */
+ if (data->state != SHT15_READING_NOTHING) { /* I/O error occurred */
+ data->state = SHT15_READING_NOTHING;
+ return -EIO;
+ } else if (ret == 0) { /* timeout occurred */
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
- sht15_connection_reset(data);
+ ret = sht15_connection_reset(data);
+ if (ret)
+ return ret;
return -ETIME;
}
@@ -567,17 +605,17 @@ static int sht15_update_measurements(struct sht15_data *data)
data->state = SHT15_READING_HUMID;
ret = sht15_measurement(data, SHT15_MEASURE_RH, 160);
if (ret)
- goto error_ret;
+ goto unlock;
data->state = SHT15_READING_TEMP;
ret = sht15_measurement(data, SHT15_MEASURE_TEMP, 400);
if (ret)
- goto error_ret;
+ goto unlock;
data->measurements_valid = true;
data->last_measurement = jiffies;
}
-error_ret:
- mutex_unlock(&data->read_lock);
+unlock:
+ mutex_unlock(&data->read_lock);
return ret;
}
@@ -595,8 +633,8 @@ static inline int sht15_calc_temp(struct sht15_data *data)
for (i = ARRAY_SIZE(temppoints) - 1; i > 0; i--)
/* Find pointer to interpolate */
- if (data->supply_uV > temppoints[i - 1].vdd) {
- d1 = (data->supply_uV - temppoints[i - 1].vdd)
+ if (data->supply_uv > temppoints[i - 1].vdd) {
+ d1 = (data->supply_uv - temppoints[i - 1].vdd)
* (temppoints[i].d1 - temppoints[i - 1].d1)
/ (temppoints[i].vdd - temppoints[i - 1].vdd)
+ temppoints[i - 1].d1;
@@ -806,7 +844,7 @@ static void sht15_bh_read_data(struct work_struct *work_s)
*/
atomic_set(&data->interrupt_handled, 0);
enable_irq(gpio_to_irq(data->pdata->gpio_data));
- /* If still not occurred or another handler has been scheduled */
+ /* If still not occurred or another handler was scheduled */
if (gpio_get_value(data->pdata->gpio_data)
|| atomic_read(&data->interrupt_handled))
return;
@@ -815,7 +853,8 @@ static void sht15_bh_read_data(struct work_struct *work_s)
/* Read the data back from the device */
val = sht15_read_byte(data);
val <<= 8;
- sht15_ack(data);
+ if (sht15_ack(data))
+ goto wakeup;
val |= sht15_read_byte(data);
if (data->checksumming) {
@@ -823,7 +862,8 @@ static void sht15_bh_read_data(struct work_struct *work_s)
* Ask the device for a checksum and read it back.
* Note: the device sends the checksum byte reversed.
*/
- sht15_ack(data);
+ if (sht15_ack(data))
+ goto wakeup;
dev_checksum = sht15_reverse(sht15_read_byte(data));
checksum_vals[0] = (data->state == SHT15_READING_TEMP) ?
SHT15_MEASURE_TEMP : SHT15_MEASURE_RH;
@@ -834,7 +874,8 @@ static void sht15_bh_read_data(struct work_struct *work_s)
}
/* Tell the device we are done */
- sht15_end_transmission(data);
+ if (sht15_end_transmission(data))
+ goto wakeup;
switch (data->state) {
case SHT15_READING_TEMP:
@@ -848,6 +889,7 @@ static void sht15_bh_read_data(struct work_struct *work_s)
}
data->state = SHT15_READING_NOTHING;
+wakeup:
wake_up(&data->wait_queue);
}
@@ -856,7 +898,7 @@ static void sht15_update_voltage(struct work_struct *work_s)
struct sht15_data *data
= container_of(work_s, struct sht15_data,
update_supply_work);
- data->supply_uV = regulator_get_voltage(data->reg);
+ data->supply_uv = regulator_get_voltage(data->reg);
}
/**
@@ -875,23 +917,21 @@ static int sht15_invalidate_voltage(struct notifier_block *nb,
struct sht15_data *data = container_of(nb, struct sht15_data, nb);
if (event == REGULATOR_EVENT_VOLTAGE_CHANGE)
- data->supply_uV_valid = false;
+ data->supply_uv_valid = false;
schedule_work(&data->update_supply_work);
return NOTIFY_OK;
}
-static int __devinit sht15_probe(struct platform_device *pdev)
+static int sht15_probe(struct platform_device *pdev)
{
int ret;
- struct sht15_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
+ struct sht15_data *data;
u8 status = 0;
- if (!data) {
- ret = -ENOMEM;
- dev_err(&pdev->dev, "kzalloc failed\n");
- goto error_ret;
- }
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
INIT_WORK(&data->read_work, sht15_bh_read_data);
INIT_WORK(&data->update_supply_work, sht15_update_voltage);
@@ -900,13 +940,12 @@ static int __devinit sht15_probe(struct platform_device *pdev)
data->dev = &pdev->dev;
init_waitqueue_head(&data->wait_queue);
- if (pdev->dev.platform_data == NULL) {
- ret = -EINVAL;
+ if (dev_get_platdata(&pdev->dev) == NULL) {
dev_err(&pdev->dev, "no platform data supplied\n");
- goto err_free_data;
+ return -EINVAL;
}
- data->pdata = pdev->dev.platform_data;
- data->supply_uV = data->pdata->supply_mv * 1000;
+ data->pdata = dev_get_platdata(&pdev->dev);
+ data->supply_uv = data->pdata->supply_mv * 1000;
if (data->pdata->checksum)
data->checksumming = true;
if (data->pdata->no_otp_reload)
@@ -918,15 +957,21 @@ static int __devinit sht15_probe(struct platform_device *pdev)
* If a regulator is available,
* query what the supply voltage actually is!
*/
- data->reg = regulator_get(data->dev, "vcc");
+ data->reg = devm_regulator_get_optional(data->dev, "vcc");
if (!IS_ERR(data->reg)) {
int voltage;
voltage = regulator_get_voltage(data->reg);
if (voltage)
- data->supply_uV = voltage;
+ data->supply_uv = voltage;
+
+ ret = regulator_enable(data->reg);
+ if (ret != 0) {
+ dev_err(&pdev->dev,
+ "failed to enable regulator: %d\n", ret);
+ return ret;
+ }
- regulator_enable(data->reg);
/*
* Setup a notifier block to update this if another device
* causes the voltage to change
@@ -937,51 +982,53 @@ static int __devinit sht15_probe(struct platform_device *pdev)
dev_err(&pdev->dev,
"regulator notifier request failed\n");
regulator_disable(data->reg);
- regulator_put(data->reg);
- goto err_free_data;
+ return ret;
}
}
/* Try requesting the GPIOs */
- ret = gpio_request(data->pdata->gpio_sck, "SHT15 sck");
+ ret = devm_gpio_request_one(&pdev->dev, data->pdata->gpio_sck,
+ GPIOF_OUT_INIT_LOW, "SHT15 sck");
if (ret) {
- dev_err(&pdev->dev, "gpio request failed\n");
+ dev_err(&pdev->dev, "clock line GPIO request failed\n");
goto err_release_reg;
}
- gpio_direction_output(data->pdata->gpio_sck, 0);
- ret = gpio_request(data->pdata->gpio_data, "SHT15 data");
+ ret = devm_gpio_request(&pdev->dev, data->pdata->gpio_data,
+ "SHT15 data");
if (ret) {
- dev_err(&pdev->dev, "gpio request failed\n");
- goto err_release_gpio_sck;
+ dev_err(&pdev->dev, "data line GPIO request failed\n");
+ goto err_release_reg;
}
- ret = request_irq(gpio_to_irq(data->pdata->gpio_data),
- sht15_interrupt_fired,
- IRQF_TRIGGER_FALLING,
- "sht15 data",
- data);
+ ret = devm_request_irq(&pdev->dev, gpio_to_irq(data->pdata->gpio_data),
+ sht15_interrupt_fired,
+ IRQF_TRIGGER_FALLING,
+ "sht15 data",
+ data);
if (ret) {
dev_err(&pdev->dev, "failed to get irq for data line\n");
- goto err_release_gpio_data;
+ goto err_release_reg;
}
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
- sht15_connection_reset(data);
+ ret = sht15_connection_reset(data);
+ if (ret)
+ goto err_release_reg;
ret = sht15_soft_reset(data);
if (ret)
- goto err_release_irq;
+ goto err_release_reg;
/* write status with platform data options */
if (status) {
ret = sht15_send_status(data, status);
if (ret)
- goto err_release_irq;
+ goto err_release_reg;
}
ret = sysfs_create_group(&pdev->dev.kobj, &sht15_attr_group);
if (ret) {
dev_err(&pdev->dev, "sysfs create failed\n");
- goto err_release_irq;
+ goto err_release_reg;
}
data->hwmon_dev = hwmon_device_register(data->dev);
@@ -994,25 +1041,15 @@ static int __devinit sht15_probe(struct platform_device *pdev)
err_release_sysfs_group:
sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group);
-err_release_irq:
- free_irq(gpio_to_irq(data->pdata->gpio_data), data);
-err_release_gpio_data:
- gpio_free(data->pdata->gpio_data);
-err_release_gpio_sck:
- gpio_free(data->pdata->gpio_sck);
err_release_reg:
if (!IS_ERR(data->reg)) {
regulator_unregister_notifier(data->reg, &data->nb);
regulator_disable(data->reg);
- regulator_put(data->reg);
}
-err_free_data:
- kfree(data);
-error_ret:
return ret;
}
-static int __devexit sht15_remove(struct platform_device *pdev)
+static int sht15_remove(struct platform_device *pdev)
{
struct sht15_data *data = platform_get_drvdata(pdev);
@@ -1030,89 +1067,33 @@ static int __devexit sht15_remove(struct platform_device *pdev)
if (!IS_ERR(data->reg)) {
regulator_unregister_notifier(data->reg, &data->nb);
regulator_disable(data->reg);
- regulator_put(data->reg);
}
- free_irq(gpio_to_irq(data->pdata->gpio_data), data);
- gpio_free(data->pdata->gpio_data);
- gpio_free(data->pdata->gpio_sck);
mutex_unlock(&data->read_lock);
- kfree(data);
return 0;
}
-/*
- * sht_drivers simultaneously refers to __devinit and __devexit function
- * which causes spurious section mismatch warning. So use __refdata to
- * get rid from this.
- */
-static struct platform_driver __refdata sht_drivers[] = {
- {
- .driver = {
- .name = "sht10",
- .owner = THIS_MODULE,
- },
- .probe = sht15_probe,
- .remove = __devexit_p(sht15_remove),
- }, {
- .driver = {
- .name = "sht11",
- .owner = THIS_MODULE,
- },
- .probe = sht15_probe,
- .remove = __devexit_p(sht15_remove),
- }, {
- .driver = {
- .name = "sht15",
- .owner = THIS_MODULE,
- },
- .probe = sht15_probe,
- .remove = __devexit_p(sht15_remove),
- }, {
- .driver = {
- .name = "sht71",
- .owner = THIS_MODULE,
- },
- .probe = sht15_probe,
- .remove = __devexit_p(sht15_remove),
- }, {
- .driver = {
- .name = "sht75",
- .owner = THIS_MODULE,
- },
- .probe = sht15_probe,
- .remove = __devexit_p(sht15_remove),
- },
+static struct platform_device_id sht15_device_ids[] = {
+ { "sht10", sht10 },
+ { "sht11", sht11 },
+ { "sht15", sht15 },
+ { "sht71", sht71 },
+ { "sht75", sht75 },
+ { }
};
+MODULE_DEVICE_TABLE(platform, sht15_device_ids);
-static int __init sht15_init(void)
-{
- int ret;
- int i;
-
- for (i = 0; i < ARRAY_SIZE(sht_drivers); i++) {
- ret = platform_driver_register(&sht_drivers[i]);
- if (ret)
- goto error_unreg;
- }
-
- return 0;
-
-error_unreg:
- while (--i >= 0)
- platform_driver_unregister(&sht_drivers[i]);
-
- return ret;
-}
-module_init(sht15_init);
-
-static void __exit sht15_exit(void)
-{
- int i;
- for (i = ARRAY_SIZE(sht_drivers) - 1; i >= 0; i--)
- platform_driver_unregister(&sht_drivers[i]);
-}
-module_exit(sht15_exit);
+static struct platform_driver sht15_driver = {
+ .driver = {
+ .name = "sht15",
+ .owner = THIS_MODULE,
+ },
+ .probe = sht15_probe,
+ .remove = sht15_remove,
+ .id_table = sht15_device_ids,
+};
+module_platform_driver(sht15_driver);
MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Sensirion SHT15 temperature and humidity sensor driver");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 08:24:10 +0000